Toxoplasmosis

Recent study

A recent scientific article (March 2016) discussed the issue of toxoplasmosis. The Robert-Koch Institute, the renowned German national scientific institute of biomedicine, has responded to the presented results.

When hearing the word toxoplasmosis, many people – including the researchers involved in the recent study – directly link it to cats and it posing a health risk. It is true that cats are the most well-known hosts of the parasite Toxoplasma gondii and humans can become infected through contacts with cat faeces.

Toxoplasma gondii parasite

T. gondii is one of the most common and successful parasites in the world – an estimated 50% of the world population is believed to have been infected at some stage of their lives and have developed immunity to it. While most infected people do not exhibit symptoms, a toxoplasmosis infection during pregnancy may have very serious consequences for the unborn child, including physical and neurological defects.

Risk evaluation

But it is important to put this risk into perspective rather than scaring cat owners or singling out cats as the main risk factor for becoming infected with toxoplasmosis at home. Rightly so, the abovementioned study confirms that this risk is indeed limited: “Cats are biologically essential in the life cycle of T. gondii, but cat exposure seems to be a less important factor compared to exposure tocontaminated food, in particular meat.”

The World Health Organisation also investigated Toxoplasmosis, lastly in 2013, and concluded regarding the main source of infection: “Human infection can result from the ingestion or handling of undercooked or raw meat containing tissue cysts.” And subsequently: “Alternatively, it can result from direct contact with cats or from the consumption of water or food contaminated by oocysts excreted in the faeces of infected cats.” 

Other sources of infection are eating unwashed fruit and vegetables or even gardening, as the parasite survives in the soil. Therefore, it is important to underline that infection predominantly comes from handling or eating raw meat and eating unwashed fruit or vegetables. Infection via cats occur less frequently, and the risk is actually easy to manage.

How to exclude risks

T. gondii can be killed at a relatively low temperature (67 oC) and also through freezing. Heat-treated pet food is always processed at higher temperatures, and storing raw food in the freezer a few days excludes the risk of toxoplasmosis.

Cat owners can avoid infections by:

•  Feeding their cat processed pet food or cooking and freezing raw food.
•  Take protective measures, such as wearing disposable gloves when cleaning the cat litter box or use a scoop; and washing their hands afterwards.
•  Cleaning the litter box with hot water every day, because T. gondii becomes viable and infectious 1-3 days after excretion.

Educating cat owners and applying basic hygiene rules in the household are the most effective measures to avoid toxoplasmosis infections.